Correlated stratigraphic sections of the lower Rochester Shale (Lewiston Member) along the Niagara Escarpment in western New York from the Niagara Gorge in the west, to Brockport, NY in the east, approximately 60 miles (96 km), showing the widespread correlation of marker beds and units. Lettered intervals A to E refer to informal submembers of the Lewiston Member. Datum or reference horizon is Lewiston B-C submember boundary. Modified from Taylor and Brett (1996).